1. Field of the Invention
The present invention relates to a light source module, and particularly to a light source module having a thermoelectric cooler which can enhance heat dissipation efficiency of the light source module.
2. Description of Related Art
Light emitting diode (LED) is a PN junction diode formed by an epitaxial P-type layer and an epitaxial N-type layer on a heavily doped semiconductor compound base. Visible light emitting diode used as light source has merits of high luminiferous efficiency, small volume and long life span. Therefore, light source modules that made of light emitting diodes are widely used in many fields such as street lamps.
A light source module, shown in FIG. 5, generally includes a plurality of LEDs 11, a printed circuit board (PCB) 12, and a heat dissipation device 13. The heat dissipation device 13 includes a base 131 and a fin unit 132 extending upwardly from the base 131. The LEDs 11 are mounted on one side of the printed circuit board 12, and the base 131 thermally contacts with an opposite side of the printed circuit board 12 to the LEDs 11. As the LEDs 11 heats up during illumination, heat is transferred in a form of heat flux from the LEDs 11 with higher temperature to the fin unit 132 with lower temperature. The printed circuit board 12 with the LEDs 11 mounted thereon is coupled on the base 131 of the heat dissipation device 13 tightly so as to reduce the transferred distance of heat flux. Thus, the heat dissipation efficiency of the heat dissipation device can be improved. However, with the limitation of the configuration and function of the light source module, reducing the transferred distance of heat flux is increasingly difficult. Therefore, the possibility of improving heat dissipation efficiency of the light source module is limited.
What is needed, therefore, is an improved light source module which can overcome the above problems.